Tests for leaks of hydraulic fluid in aircraft landing gear are known that seek to determine whether the dynamic seal(s) present between the strut and the sliding rod of the landing gear leg do indeed provide sealing without allowing any hydraulic fluid to pass to the outside of the landing gear strut, particularly along the sliding rod, when the landing gear is under pressure. In general, the strut has a bearing including at least one dynamic seal for rubbing against the sliding rod, the bearing being prevented from moving axially by a stop nut provided with a wiper seal.
These tests are generally performed as follows:                pressurizing said landing gear with the hydraulic fluid;        ceasing to pressurize the landing gear;        partially dismantling the stop nut of the bearing, where this is essential given that the wiper seal can prevent leakage running down from a leak in the dynamic sealing means; and        inspecting the rod to verify whether any leakage is present thereon, and thus verify whether a leak is present.        
Nevertheless, it has been found that partially dismantling the stop nut for preventing movement in translation together with its wiper seal can damage the wiper seal, thus requiring the landing gear leg to be dismantled completely in order to be able to remove the stop nut and thus replace its wiper seal. Such a procedure takes time and delays putting the landing gear into service.